Pipe coupling



FIG. 1 is a perspective view of a first embodiment of our design for a pipe coupling;

FIG. 2 is a side view of the pipe coupling shown in FIG. 1, the opposite side, the top and bottom views being identical thereto;

FIG. 3 is an end view of the pipe coupling shown in FIG. 1, the opposite end view being identical;

FIG. 4 is a perspective view of a second embodiment of our design for a pipe coupling;

FIG. 5 is a side view of the pipe coupling shown in FIG. 4, the opposite side, the top and bottom views being identical thereto; and,

FIG. 6 is an end view of the pipe coupling shown in FIG. 4, the opposite end view being identical.

The broken lines shown in FIGS. 4 and 6 are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a pipe coupling, as shown and described. 